Remember those girls in high school who liked to dot their i’s with ♥’s? It was such an overly cute affectation that it disguised any depth that might lie behind their penmanship. Welcome “L!fe Happens” (note the exclamation mark), a well-acted if mild and silly comedy written by Kat Coiro, the director, and Krysten Ritter, the star.

Ms. Ritter (now in “Don’t Trust the B – – – – in Apartment 23” on television) plays Kim, a happening young woman who dreams of creating a doggie mall but, darn it, loses a race for the last condom in the house she shares with two women. So Kim becomes a single mother, and her determined roommate Deena continues writing academia-infused “Sex and the City”-style self-help books. The other roommate goes from odd job to odd job until landing a spot on a reality show starring women who compete to remain virgins.

Some capable actors, however, go a ways toward making those movie clichés, at least in places, pleasant. Ms. Ritter and the handsome Geoff Stults have appealing moments as the will-they-get-together-of-course-they-will couple. Performances by the great Kristen Johnston (as a Movie Rich Diva) and the slumming Justin Kirk (as a Movie Eccentric) earn laughs. Most appealing is Kate Bosworth, whose sharp humor as Deena has a bite that dares you to dismiss her. Even if you might dismiss her film.